The invention relates to a remote control device by cable for motor vehicle equipment such as, for example, a heating and/or air conditioning unit of the passenger compartment of such a vehicle.
The device of the invention is of the type comprising a cable, the ends of which are each provided with a connecting piece, a sleeve in which the cable can slide so that the ends of the cable project from the ends of the sleeve, as well as clips that are capable of attaching the ends of the sleeve onto parts of the vehicle.
In known devices of this type, one of the clips is generally fixed to a control panel provided on the dashboard of the vehicle, whereas the other clip is fixed to the actual equipment.
Normally, one of the ends of the cable is provided to be connected to the end of a pivoting lever that is operated by a control knob, whereas the other end of the cable is provided to be connected to the end of another lever which operates a mobile element of the equipment.
In the case of a heating and/or air conditioning unit of a motor vehicle, this latter lever most frequently serves to activate the rotational displacement of a pivoting flap which controls a flow of air.
Such control devices by cable raise in particular questions of control, given that it is necessary to be able to bring two limit of travel positions of the control device (generally a rotary knob) to correspond with two respective limit of travel positions of a movable element of the equipment of the vehicle.
In other words, it is necessary to adjust accurately the difference between the length of the cable (defined between its two ends), and the length of the sleeve (defined between its two ends or between its two clips). This difference in length is also called xe2x80x9cfunctional projectionxe2x80x9d.
The regulation of this difference in length is difficult to control given that the sleeve and the cable both have a dimensional tolerance. In fact, the tolerance of the sleeve may reach values of more or less 1 mm, even more or less 2 mm, whereas the cable itself has a dimension tolerance of more or less 1 mm. As a result the abovementioned difference, corresponding to the value of the functional projection, may have a tolerance of more or less 3 mm in relation to its nominal value.
Different solutions have already been proposed to try to resolve this problem.
One solution consists of regulating the xe2x80x9cfunctional projectionxe2x80x9d directly on the-assembly line of the vehicle by placing a fastening clamp of the sleeve at one of the ends of said sleeve, generally on the side of the housing of the equipment. This solution requires access to an experienced operator, which complicates the mounting operations and also increases their cost.
The regulation of the dimension of the xe2x80x9cfunctional projectionxe2x80x9d before assembly on the assembly line is also known. This regulation may be achieved, for example, by a screw regulating device situated in the middle of the remote control device, or by a device with a clamp fitting, as disclosed by document EP 0 492 289. There too, these solutions are long and expensive to implement.
Other solutions consist in using self-adjusting spring devices between the cables and the sleeve. These devices are expensive and do not ensure great reliability.
The object of the invention is in particular to overcome the above-mentioned drawbacks.
In particular, it aims to obtain a remote control device of the type defined above, which allows a precise regulation of the functional projection to be ensured before mounting on the vehicle.
For this purpose the invention proposes a remote control device of the type defined in the introduction, in which the connecting pieces and the clips are overmoulded respectively onto the cable and the sleeve from the same plastic material.
Thus, the two connecting pieces and the clips may be overmoulded in well-defined respective positions, which allows the xe2x80x9cfunctional projectionxe2x80x9d to be adjusted each time with a slight tolerance.
The invention advantageously specifies that a connecting piece and an associated clip are overmoulded simultaneously with a precise control of the distance between the connecting piece and the clip.
In a preferred embodiment of the invention, the two connecting pieces are identical. The latter preferably each have a shape generated by revolution, in particular a substantially spherical shape, preferably in relation to the axis of the cable.
In this preferred embodiment of the invention, the two clips are identical.
Thus, when the two connecting pieces are identical and the two clips are also identical, the remote control offers a symmetry and it may therefore be installed in any manner, without it being advisable to choose a particular mounting direction.
In the case in which the two clips are identical, they may have a shape generated by revolution, in particular a substantially cylindrical shape, preferably in relation to the axis of the sleeve. Such a shape is essentially suitable for a radial connection of the clip onto a support forming part of the vehicle.
In another refinement, each clip comprises axial snapping means and radial snapping means for the connection of the clip at will, either onto a support with axial attachment, or onto a support with radial attachment.
In this particular case, it is advantageously specified that each clip comprises a split muff for the axial snapping, which depends on a ring for the radial snapping, the muff being situated on the side the end of the sleeve.
This split muff advantageously comprises axial slots which between them delimit axial lugs equipped with respective hooks capable of bending radially.
In another embodiment of the invention, the two clips are different.
Thus, one of the clips may comprise a ring capable of being snapped radially into a receiver block of the vehicle, whereas the other clip may comprise a ring equipped with a snapping member capable of being received in another receiver block of the vehicle.
In the different embodiments of the invention, the connecting pieces and the clips are preferably made of a thermoplastic material, which is advantageously filled.
It may involve, for example, a material of the polyoxymethylene (POM) type, or of the polypropylene type, filled with talc.
From another angle, the invention relates to a process for manufacturing a remote control device such as that previously defined, which comprises the following operations:
a) providing for a sleeve in which a cable is threaded in such a manner that the ends of the cable project beyond the ends of the sleeve; and
b) overmoulding, from the same plastic material, two connecting pieces respectively onto the two ends of the cable and two clips respectively onto the two ends of the sleeve.
In operation b), it is advantageously specified that a connecting piece and an associated clip are simultaneously overmoulded with a precise control of the distance between the connecting piece and the clip.
Thus, it may be specified that operation b) firstly comprises the simultaneous overmoulding of a connecting piece and of an associated clip, then the simultaneous overmoulding of another connecting piece and an associated clip.